Non-polluting chimney

ABSTRACT

A non-polluting chimney comprising a flue for the products to be discharged, a covering of heat-insulating material surrounding the flue and a casing of plastics material surrounding the covering. A specific embodiment comprises superposed chimney sections whose outer casings have end flanges which are clamped together, the corresponding flue sections being suspended from the casings.

United States Patent [19] Pint 1 1 Oct. 2, 1973 1 NON-POLLUTING CHIMNEY[76] Inventor: Jacques Claude Michel Piot, 171,

Rue Join-Lambert, 76 BoisGuillaume, France 22 Filedz Jan. 28, 1972 [21]Appl. No.: 221,630

[30] Foreign Application Priority Data Jan. 28, 1971 France 7103842 [52]U.S. Cl ..98/58,110/184,138/149,

51] Int. Cl E04h 12/28 [58] Field of Search ..'98/58, 59,60;110/184;138/149,150, 155

I56] References Cited UNITED STATES PATENTS Plummer 138/149 X l, E g

2,451,145 10/1948 Baker et al. 1. 138/149 2,906,317 9/1959 Keyes 138/149X 2,936,792 5/1960 MacCraekcn et a1. 138/150 X 3,330.233 7/1967 Clements110/184 2,342,058 2/1944 Morris 98/58 X Primary Examiner-Wi1liam F.()Dea Assistant ExaminerPeter D. Ferguson Attorney-John C. Holman et a1.

[57] ABSTRACT A non-polluting chimney comprising a flue for the productsto be discharged, a covering of heat-insulating material Surrounding theflue and a casing of plastics material surrounding the covering.

A specific embodiment comprises superposed chimney sections whose outercasings have end flanges which are clamped together, the correspondingflue sections being suspended from the casings.

11 Claims, 9 Drawing Figures lulmll a PATENTED BET 2 75 SHEET 2 BF 2NON-POLLU'IING CHIMNEY The present invention relates to a non-pollutingchimney, that is a chimney which discharges products of combustion atsufficient height, temperature and velocity to avoid noticeablypolluting the surrounding atmosphere.

The obtainment of a sufficiently high discharge velocity in the upperpart of a chimney depends on maintaining a relatively high temperatureof the product being discharged. This relatively high temperature ismoreover beneficial since it prevents the production of corrosiveproducts and smoky charcoal. The maintenance of such a temperaturerequires heat-insulating the chimney so as to avoid an excessive coolingof the product discharged. For this purpose, chimneys have beenconstructed having a discharge flue which is surrounded by a sleeve ofaluminium whose inner surface reflects back onto the flue the heat givenoff by the latter and thus achieves an efficient heat insulation.However, these chimneys of aluminium are relatively weak and finallybecome oxidized both externally and internally. Consequently, theirreflecting power diminishes and this has for result' to reduce the heatinsulating effect, increase the heat losses in the chimney and producean undesirable drop in the temperature of the products discharged.

An object of the present invention is to overcome these drawbacks andprovide an improved nonpolluting chimney whereby it is possibleto'satisfy the various requirements of the art in an improved manner.

The invention provides a non-polluting chimney comprising a flue for theproducts to be discharged, a covering of heat-insulating materialsurrounding the flue, and a casing of plastics material surrounding thecovering.

In a particular embodiment of the invention, the chimney comprises aplurality of superposed sections each of which comprisesa'heat-insulated flue section and a casing section provided at both endswith assembly flanges and each flue section has a collar at each of itsends, the adjacent flanges of two successive casing sections-definingrecesses which receive the adjacent collars of the corresponding twoflue sections.

In another embodiment of the invention, the chimney comprises aplurality of superposed sections each of which has a heat-insulated fluesection and a casing section having at both ends assembly flanges, eachflue section being suspended from the upper flange of the correspondongcasing section. Thus, when the temperature of the products to bedischarged is very high, for example 300-350C in the case of products ofcombustion and with a flue of stainless steel or aluminium, theexpansion allowed by such an assembly may be very considerable withoutresulting in stresses that adversely affect the correct performance ofthe chimney over a period of time.

Further features and advantages of the invention will be apparent fromthe ensuing description with reference to the accompanying drawings.

In the drawings 7 FIG. 1 is a partial half-sectional andhalf-elevational view of a chimney according to a first embodiment ofthe invention; 7

FIG. 2 is a sectional view taken on line A-A of FIG.

FIG. 3 is a sectional view of the assembly of two sections of thechimney;

FIG. 4 is a vertical sectional view of the assembly of the crowning ofthe chimney shown in FIG. 1;

FIG. 5 is a plan view of a fastener for the guying of the chimney;

FIG. 6 is an elevational view, with parts cut away, of a chimneyaccording to a second embodiment of the invention, and

FIGS. 7, 8 and 9 are partial diametral sectional views on an enlargedscale of three parts of the chimney shown in FIG. 6 respectivelycorresponding to the assembly of two chimney sections, the assembly ofthe crowning with the upper chimney section and the assembly of thelower chimney section with the associated installation.

The non-polluting chimney shown in FIGS. 1-5, comprises a flue 1 fordischarging the products of combustion, a covering 2 of heat-insulatingmaterial surrounding the flue 1 and a casing 3 of plastics materialsurrounding the covering 2. The flue 1 is of a material resisting theheat and corrosive attack of the products of combustion to bedischarged. This flue may be of metal, in particular steel or stainlesssteel. In order to compensate the effects of expansions due to heat, theflue 1 may be provided with folded portions in the form of bellows, butit is more advantageous to employ a flue constructed in the known mannerby the rolling and seaming of a band of metal in the form of a helix 4,the seaming allowing absorption of the expansions consequent to theheating of the flue 1. If desired, the flue may have a helicalreinforcing groove parallel to the helix 4.

Although other heat-insulating means may be employed, theheat-insulating covering 2 is preferably composed of rock wool. Thecovering is held on the flue l by bindings 5 or metal netting.

An annular space 6 is formed between the outer face of the covering 2and the inner face of the casing 3. The latter is preferably ofself-extinguishing stratified polyester and coloured throughout itsthickness. The casing 3 can be constructed by the assembly about thecovering 2 of two semi-shells 7 and 8 which are welded together by thesupply of plastics material at 9 and I0, lap joints II and 12 beingadhered to these welds. If need be, for the purpose of for exampledismantling the chimney, these welds are broken to separate the twosemi-shells 7 and 8 which may be re-assembled by a further welding.Longitudinal ribs 13 stiffen the casing 13.

Except as concerns short chimneys, the chimneys according to theinvention are constructed by the assembly of a plurality of sectionseach of which comprises a heat-insulated flue surrounded by a casing ofplastics material.

In order to preclude heat losses which would have for effect to reducethe temperature of the products of combustion and render these productscorrosive or harmful, not only the flues of these sections areheatinsulated, as explained hereinbefore, but the connection of the flueof one chimney section to the flue of the chimney section immediatelyabove or below is arranged in such manner as to avoid a thermalconnection or bridge between the two flues or between these flues andthe atmosphere surrounding the chimney. For this purpose, the flues I,14 of the superposed chimney sections 15, 16 terminate respectively inidentical collars or flanges 17, 18 which are in facing relation. Thesecollars may be welded to the flues. A heatinsulating seal or gasket 19is interposed between these collars to prevent any direct contactbetween the flues 1, 14 or between their collars 17, 18. In theconventional case of circular cylindrical flues, the collars 17, 18 andthe seal 19 are in the form of circular rings and a double flange 20 onthe seal 19 enables the collars, and consequently the correspondingflues, to be mutually centered. On the side opposed to the seal 19, eachcollar 17 or 18 receives an annular heat-insulating seal or gasket 21 or22, each seal being in two semi-circular parts. The seals 19, 21 and 22may be of an asbestos material.

One chimney section is fixed to a superposed section by means of flangesintegral with the casings of the sections, these flanges being heldassembled by bolting. The assembly of these flanges ensures the assemblyof the aforementioned collars and seals and the connection of thecorresponding flues. Thus, the casing 3 of chimney section 15 forms aflange 23 which is fitted on the flange 24 integral with the casing 25of the chimney section 16. Bolt means 26 assemble the flanges 23 and 24.Each flange 23 or 24 defines a recess 27 or 28 receiving respectivelythe collar 17 and seal 21 of the section 15 and the collar 18 and seal22 of the section 16.

Annular grooves 29 and 30 serve to center the seals 21 and 22 withrespect to the flanges 23 and 24. With the seal 19 in position betweenthe two collars 17 and 18, the tightening of the bolt means 26 clampsthe seals 19, 21 and 22 against the collars l6 and 17 and consequentlyholds these collars assembled and interconnects the corresponding flues1 and 14.

The extent of the upper flange such as 23 of an assembly of flangescovers or overlaps the lower flange such as 24. This covering oroverlapping precludes infiltrations of water between the flanges.

According to the invention, the crowning of the chimney comprises amember 31 of epoxy glass which fits on the upper flange 32 of the upperchimney section 15. The member 31 defines a convergent portion whichaccelerates the discharge of the products. This member 31 is fixed bybolt means 33 the tightening of which maintains'the upper end collar 34of the flue 1 in position by the clamping of heat-insulating seals 35and 36 between the member 31 and a recess 36a in the flange 32.

Curved members 37 having apertures 38 and 39 adapted to be engaged onthe bolt means such as 26 enable the chimney to be guyed, thecorresponding guy being attached at 40.

By way of a modification, in order to compensate possible differences inlength, one of the collars carried by a flue section can be fixed to asleeve which is slidablymounted on the flue and provided with a sealaffording a fluidtight sliding assembly.

The collars may also be provided with preferably heat-insulating bossesand apertures receiving these bosses so as to center the facing collars,such as 17 and 18.

The chimney described hereinbefore affords, in addition to otheradvantages, the advantage of being light and very easily erected. It maybe completely dismantled and has an attractive external appearance. Noservicing or maintenance of its outer part is required.

The chimney illustrated in FIGS. 6 to 9 comprises an inner flue throughwhich the products to be discharged flow, a covering of heat-insulatingmaterial surrounding the flue and a casing of plastics materialsurrounding this covering. It comprises a plurality of superposedsections each of which comprises a flue section 41, a heat-insulatingmaterial covering section 42 and a casing section 43.

Each casing section 43 is constituted by a cylindrical tube which has ateach end, moulded in one piece therewith (which increases itsstiffness), an annular as sembly flange 44 having an annular peripheralportion 45 parallel to the rest of the flange but axially offsetrelative thereto in the direction of the neighbouring chimney section.This tube has in its upper and lower end parts 43a an increased wallthickness equal to the thickness of the flanges so as to reinforce thecasing assembly region. Each casing section bears against the lowercasing section by the direct contact between the annular peripheralportions 45 of their flanges and by the bearing of the remaining parts44 of these flanges against each other through two annular asbestosseals or gasket 46 between which is interposed a thick metal ring 47 thefunction of which will be explained hereinafter. Two rows of bolt means48 and 49 respectively hold the assembly together in the region of theseals 46 and in the region of the peripheral portions 45. The peripheralportion 45 of the lower flange of each casing section has a cylindricaldepending flange portion 450 which covers the peripheral portion 45 ofthe upper flange of the underlying casing section. Outer ribs 50 areprovided along generatrices of the casing so as to stiffen the latter.

Each flue 41 consists of a metal band which is wound in the form of ahelix and interlocked or seamed externally so as to constitute acylindrical conduit which is suspended from a cylindrical socket or tube51 of stainless steel having in its lower part a stepped portion 52 onwhich the section 41 is fitted and secured by rivets 53 and in its upperpart a formed-over outer flange 54. The flange 54 of the socket 51 bearson the upper edge of a cylindrical sleeve 55 of mild steel which has aslightly greater inside diameter and is connected in its upper part tothe metal ring 47 by a plurality of radial arms 56 which are in a numberwhich varies with the diameter of the chimney and are reinforced bymetal gussets 57 which bear against the sleeve 55. The length of eachflue section is such that the lower part of the flue section extendsinto the support socket 51 of the flue section located thereunder to theextent of about one half of the length of the socket 51. The flue is forexample constructed from stainless steel when the products to bedischarged are products of the combustion of fuel oil since theseproducts contain a notable amount of S0 or from aluminium when theproducts are the products of combustion of gas, these productscontaining a notable amount of H 0.

As concerns the corresponding heat-insulating covering section 42composed for example of rock wool, it has the shape of a cylindricalring which is supported externally by a galvanized netting 58 which isclosed upon itself and clamped to the heat-insulating covering sectionby steel wires 58a. The netting 58 is also fixed at various places alongits length to the flue section by cylindrical bands of sheet material 59which surround, with interposition of an asbestos insulation 60, theflue section and carry steel pins 61 which extend through the heatinsulation covering and are combined with retaining plates 62 behind thenetting 58. Internally, the heat-insulating covering is in contact withthe flue 41 throughout its surface.

Thus, the various flue sections are fitted together by socketconnections and this avoids the provision of a seal and moreover allowsin the socket an axial expansion which is as large as could possiblyoccur. Further, radial expansions are allowed by a sufficient clearancebetween the socket 51 and the associated support sleeve 55. The fluesections are therefore assembled with no welding which would tend to setup stresses and the assembly is fully floating.

Further, each flue section and the heat-insulating covering sectionfixed thereto are entirely and solely supported by the correspondingcasing section 43. This renders the whole of the chimney self-supportingby its casing of plastics material so that no servicing or maintenanceis required. The casing is preferably of stratified polyester reinforcedwith fibre glass so as to possess the required strength and stiffness.it is preferably formed in a mould having a mirror-polished surface soas to possess perfectly smooth surfaces.

The action of the bolt means 48 and 49 results, in respect of the innerrow of bolt means 48, in an excellent stability of the metal ring 47clamped between the two flanges which thusconstitutes in itself a verystrong reinforced flange,and, in respect of the outer row of bolt means49, in a good seal against entry of rain water, this seal being stillfurther enhanced by the existence of the formed-over peripheral portion45a on the upper flange.

The heat exchanges are reduced to a minimum since a large empty space 63is provided between the heatinsulating covering 42 and the outer casing43 so that the chimney has two insulating layers of which one isconstituted by the heat-insulating covering 42 and the other by the airin the space 63. The asbestos seals 46 preclude transmission of heat inthe region of the suspension of the flue sections and the creation ofcold regions.

The space 63 moreover ensures that the expansion of the flue 41 has noeffect on theouter casing and this reduces the number of adjustmentsrequired for the guying of the chimney. This guying is achieved by meansof guy cables 64 fixed to plates 65 which are mounted on the flanges 44either above and held fast by the bolt means 49, or below and held fastby the bolt means 48.

Thedescribed structure of the chimney enables the exhaust noises,resulting for example from the transmission of the noises of combustion,to be eliminated without loss of pressure in the products to bedischarged. This elimination of noises is still further facilitated bythe possible provision of apertures 66 in the wall of the flue sections41, except possibly the lower section in which when the products to bedischarged are gases, these gases expand whereas in the followingsections they are already less hot.

The perfect heat insulation of the chimney imparts to the products to bedischarged a particularly high upward velocity which creates throughoutthe height of the chimney a depression in the gas flue 41 of the orderof 3 to mm of water; thus, owing to this permanent depression, no escapeof product to the exterior is possible. Even an accidental increase inpressure, for example caused by the installation at the upstream end ofthe chimney, could not result in an escape of product since the outercasing 43 is strictly fluidtight in the region of the assembly of theflanges, owing to the perfectly smooth surface condition of theseflanges which are produced by a moulding operation, as mentionedhereinbefore.

The surface condition of the gas flue precludes attachment of soot andrenders chimney sweeping unnecessary. The assembly of the sections ofthe chimney by means of floating socket connections allows an extremelyeasy erection in addition to freedom of expansion.

The chimney has a very high resistance to corrosion and hightemperatures.

However, the essential advantage afforded by the structure describedresulting from an excellent heat insulation is, as in the case of thefirst embodiment described, the avoidance of formation of smoky charcoalwhich is constituted by a complex of carbon and nascent H SO and is inthe form of black fluff which oxidizes the metal surfaces onto which itfalls.

The nature of the gasflue (for example stainless steel or aluminum) andthe perfect heat insulation enable the chimney to withstand gastemperatures of the order of 500C.

The assembly of the crowning of the chimney with the upper section andthe assembly of the lower section with the chimney support are achievedwith slight modiflcations in the assembly of the chimney section witheach other.

The assembly of the crowning member 67, which is composed of epoxy resinreinforced with fibre glass, has a centre portion having a convergentshape so as to accelerate the flow of the discharged products and a wideflange 68 around the centre portion which has on its periphery the sameshape as the flange 44 of the casing sections, the fixing being achievedin the same manner by means of two rows of bolt means 48 and 49 and withinterposition of asbestos rings except that the ring 46a located abovethe ring 47 supporting the upper flue section is much larger so as tooverlap entirely this ring, the connecting arms of the ring 47 and theformed-over outer flange of the flue section.

The lower section of the chimney bears against a connecting memberconstituted by an annular base 69 which is fixed on the support 70 forthe chimney (for example smokebox of a boiler, base of metal or masonry,flue or raised portion) which carries two cylindrical sleeves 71 and 72of which the first fits with a slight clearance inside the lower fluesection and the second surrounds the heat-insulating covering and thecorresponding netting and carries in its upper part a steel annularflange 73 on which the lower flange of the lower casing section bears,these two flanges being assembled by two rows of bolt means 48 and 49 inthe same manner as the other flanges but with the interposition of asimilar seal 46 and another annular seal of asbestos 46b which extendsradially to the formed-over peripheral portion 450 of the casing.

As in the entrance of the chimney the pressure is usually neutral or isa few millimetres, the arrangement of the flue 41 outside the sleeve 71precludes the passage of gases into the rock wool which woulddeteriorate the latter. This arrangement also facilitates directing therain water which may flow along the interior of the flue in thedirection of the annular space between the two sleeves and an outerdrain pipe 74.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is 1. A non-polluting chimney comprising aplurality of superposed sections, each section comprising in combinationa flue section for the products to be discharged, a covering section ofheat-insulating material surrounding the flue section, a casing sectionof plastics material surrounding the covering section, each casingsection having an upper flange adjacent the upper end of the casingsection and a lower flange adjacent the lower end of the casing sectionfor assembling the chimney sections to each other, means forinterconnecting the flanges of adjacent casing sections, and means forsuspending each flue section from the upper flange of the correspondingcasing section.

2. A chimney as claimed in claim 1, wherein in respect'of two successivechimney sections, the lower flange of the upper casing section has adepending flange portion which surrounds the upper flange of the lowercasing section.

3. A chimney as claimed in claim 1, comprising means securing eachheat-insulating covering section to the corresponding flue section, anempty space being defined between said heat-insulating covering sectionand the corresponding casing section.

4. A chimney as claimed in claim 1, further comprising a base structurehaving an outer sleeve, an inner sleeve from which the products to bedischarged issue, a flange integral with the outer sleeve, and means forsecuring the casing section of the lowermost of said chimney sections tothe flange integral with said outer sleeve,

said inner sleeve upwardly extending into, and being in close proximityto, the flue section of said lowermost chimney section.

5. A non-polluting chimney comprising a plurality of superposedsections, each section comprising in combination a flue section for theproducts to be discharged, a covering section of heat-insulatingmaterial surrounding the flue section, a casing section of plasticsmaterial surrounding the covering section, each casing section having anupper flange adjacent the upper end of the casing section and a lowerflange adjacent the lower end of the casing section for assembling thechimney sections to each other, means for interconnecting the flanges ofadjacent casing sections, and means for suspending each flue sectionfrom the upper flange of the corresponding casing section, said meanscomprising a structure in fixed relation to said upper flange and acollar in fixed relation to said flue section and bearing on saidstructure.

6. A chimney as claimed in claim 5, wherein said structure comprises aninner cylindrical sleeve, an outer ring in fixed relation to said upperflange, and radially-extending arms interconnecting the innercylindrical sleeve and outer ring.

7. A chimney as claimed in claim 5, wherein said structure has a portionwhich is interposed between said upper flange and the lower flange ofthe casing section located thereabove, clamping means clamping saidstructure portion between said upper and lower flanges.

8. A chimney as claimed in claim 7, comprising seals of heat-insulatingmaterial interposed between said portion of said structure and theflanges between which said portion is clamped.

9. A chimney as claimed in claim 5, comprising a cylindrical sockethaving an upper end portion integral with said collar and a lower endportion in fixed relation to the flue section.

10. A chimney as claimed in claim 9, wherein in respect of twosuccessive chimney sections, the upper flue section is in fittingrelation to the socket of the lower flue section.

11. A non-polluting chimney comprising a flue for the products to bedischarged, a covering of heatinsulating material surrounding the flueand a casing of plastics material surrounding the covering, the casingbeing composed of stratified polyester reinforced with fibre glass andbeing self-extinguishable.

1. A non-polluting chimney comprising a plurality of superposedsections, each section comprising in combination a flue section for theproducts to be discharged, a covering section of heatinsulating materialsurrounding the flue section, a casing section of plastics materialsurrounding the covering section, each casing section having an upperflange adjacent the upper end of the casing section and a lower flangeadjacent the lower end of the casing section for assembling the chimneysections to each other, means for interconnecting the flanges ofadjacent casing sections, and means for suspending each flue sectionfrom the upper flange of the corresponding casing section.
 2. A chimneyas claimed in claim 1, wherein in respect of two successive chimneysections, the lower flange of the upper casing section has a dependingflange portion which surrounds the upper flange of the lower casingsection.
 3. A chimney as claimed in claim 1, comprising means securingeach heat-insulating covering section to the corresponding flue section,an empty space being defined between said heat-insulating coveringsection and the corresponding casing section.
 4. A chimney as claimed inclaim 1, further comprising a base structure having an outer sleeve, aninner sleeve from which the products to be discharged issue, a flangeintegral with the outer sleeve, and means for securing the casingsection of the lowermost of said chimney sections to the flange integralwith said outer sleeve, said inner sleeve upwardly extending into, andbeing in close proximity to, the flue section of said lowermost chimneysection.
 5. A non-polluting chimney comprising a plurality of superposedsections, each section comprising in combination a flue section for theproducts to be discharged, a covering section of heat-insulatingmaterial surrounding the flue section, a casing section of plasticsmaterial surrounding the covering section, each casing section having anupper flange adjacent the upper end of the casing section and a lowerflange adjacent the lower end of the casing section for assembling thechimney sections to each other, means for interconnecting the flanges ofadjacent casing sections, and means for suspending each flue sectionfrom the upper flange of the corresponding casing section, said meanscomprising a structure in fixed relation to said upper flange and acollar in fixed relation to said flue section and bearing on saidstructure.
 6. A chimney as claimed in claim 5, wherein said structurecomprises an inner cylindrical sleeve, an outer ring in fixed relationto said upper flange, and radially-extending arms interconnecting theinner cylindrical sleeve and outer ring.
 7. A chimney as claimed inclaim 5, wherein said structure has a portion which is interposedbetween said upper flange and the lower flange of the casing sectionlocated thereabove, clamping means clamping said structure portionbetween said upper and lower flanges.
 8. A chimney as claimed in claim7, comprising seals of heat-insulating material interposed between saidportion of said structure and the flanges between which said portion isclamped.
 9. A chimney as claimed in claim 5, comprising a cylindricalsocket having an upper end portion integral with said collar and a lowerend portion in fixed relation to the flue section.
 10. A chimney asclaimed in claim 9, wherein in respect of two successive chimneysections, the upper flue section is in fitting relation to the socket ofthe lower flue section.
 11. A non-polluting chimney comprising a fluefor the products to be discharged, a covering of heat-insulatingmaterial surrounding the flue and a casing of plastics materialsurrounding the covering, the casing being composed of stratifiedpolyester reinforced with fibre glass and being self-extinguishable.